function [ y ] = delta_a( acceleration_x_1, acceleration_y_1, acceleration_z_1, acceleration_x_2, acceleration_y_2, acceleration_z_2 )

delta_x = acceleration_x_1 - acceleration_x_2;
delta_y = acceleration_y_1 - acceleration_y_2;
delta_z = acceleration_z_1 - acceleration_z_2;

y = sqrt(delta_x * delta_x + delta_y * delta_y + delta_z * delta_z);

end